Simplify the following expression: $a = \dfrac{1}{2q} + \dfrac{7}{3q}$
Explanation: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $2q$ and $3q$ $\lcm(2q, 3q) = 6q$ $ a = \dfrac{3}{3} \cdot \dfrac{1}{2q} + \dfrac{2}{2} \cdot \dfrac{7}{3q} $ $a = \dfrac{3}{6q} + \dfrac{14}{6q}$ $a = \dfrac{3 +14}{6q}$ $a = \dfrac{17}{6q}$